function check(form) {
            var p1 = form.passwd1;
            var p2 = form.passwd2;
            if (p1.value != p2.value) {
                p2.oninvalid();
                return false;
            }
            return true;
        }
        onload = function() {
            var p2 = document.forms["my_f1"].passwd2;
            p2.oninvalid = function() {
                this.setCustomValidity("密码不一致，请重新输入");
            }
            p2.oninput = function() {
                this.setCustomValidity("");
            }
 
        }